Which organism is commonly associated with swimmer's ear?

Swimmer's ear, also known as otitis externa, is an infection of the outer ear canal and is frequently associated with water exposure. Pseudomonas aeruginosa is the most commonly implicated organism in swimmer's ear because it thrives in moist environments. This bacterium is opportunistic and can lead to infections particularly in individuals who have had prolonged exposure to water, such as swimmers or those who use hot tubs.

Pseudomonas aeruginosa is known for its ability to colonize damp areas and evade the immune response. Its presence in warm, humid swimming conditions can facilitate the entry and multiplication of the bacteria in the ear canal, leading to symptoms of pain, itching, and discharge.

In contrast, other organisms listed, like Salmonella and Escherichia coli, are generally associated with gastrointestinal infections, and Staphylococcus aureus primarily causes skin infections and other conditions, but they are not typically linked to the ear infections resulting from swimming activities. Thus, the focus on Pseudomonas aeruginosa is crucial for understanding the etiology of swimmer's ear and highlights the importance of maintaining ear hygiene, especially after swimming.